[PATCH 1/3 v2] Add Directed EOI support to APIC emulation

[Gleb Natapov <gleb@redhat.com>]

Directed EOI is specified by x2APIC, but is available even when lapic is
in xAPIC mode.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
---
 arch/x86/include/asm/apicdef.h |    2 ++
 arch/x86/kvm/lapic.c           |   13 ++++++++-----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/apicdef.h b/arch/x86/include/asm/apicdef.h
index 7ddb36a..74ca38f 100644
--- a/arch/x86/include/asm/apicdef.h
+++ b/arch/x86/include/asm/apicdef.h
@@ -14,6 +14,7 @@
 
 #define	APIC_LVR	0x30
 #define		APIC_LVR_MASK		0xFF00FF
+#define		APIC_LVR_DIRECTED_EOI	(1 << 24)
 #define		GET_APIC_VERSION(x)	((x) & 0xFFu)
 #define		GET_APIC_MAXLVT(x)	(((x) >> 16) & 0xFFu)
 #ifdef CONFIG_X86_32
@@ -40,6 +41,7 @@
 #define		APIC_DFR_CLUSTER		0x0FFFFFFFul
 #define		APIC_DFR_FLAT			0xFFFFFFFFul
 #define	APIC_SPIV	0xF0
+#define		APIC_SPIV_DIRECTED_EOI		(1 << 12)
 #define		APIC_SPIV_FOCUS_DISABLED	(1 << 9)
 #define		APIC_SPIV_APIC_ENABLED		(1 << 8)
 #define	APIC_ISR	0x100
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 2e02865..db0c6ae 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -54,7 +54,8 @@
 
 #define APIC_LVT_NUM			6
 /* 14 is the version for Xeon and Pentium 8.4.8*/
-#define APIC_VERSION			(0x14UL | ((APIC_LVT_NUM - 1) << 16))
+#define APIC_VERSION			(0x14UL | ((APIC_LVT_NUM - 1) << 16) | \
+					 APIC_LVR_DIRECTED_EOI)
 #define LAPIC_MMIO_LENGTH		(1 << 12)
 /* followed define is not in apicdef.h */
 #define APIC_SHORT_MASK			0xc0000
@@ -442,9 +443,11 @@ static void apic_set_eoi(struct kvm_lapic *apic)
 		trigger_mode = IOAPIC_LEVEL_TRIG;
 	else
 		trigger_mode = IOAPIC_EDGE_TRIG;
-	mutex_lock(&apic->vcpu->kvm->irq_lock);
-	kvm_ioapic_update_eoi(apic->vcpu->kvm, vector, trigger_mode);
-	mutex_unlock(&apic->vcpu->kvm->irq_lock);
+	if (!(apic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI)) {
+		mutex_lock(&apic->vcpu->kvm->irq_lock);
+		kvm_ioapic_update_eoi(apic->vcpu->kvm, vector, trigger_mode);
+		mutex_unlock(&apic->vcpu->kvm->irq_lock);
+	}
 }
 
 static void apic_send_ipi(struct kvm_lapic *apic)
@@ -683,7 +686,7 @@ static void apic_mmio_write(struct kvm_io_device *this,
 		break;
 
 	case APIC_SPIV:
-		apic_set_reg(apic, APIC_SPIV, val & 0x3ff);
+		apic_set_reg(apic, APIC_SPIV, val & 0xfff);
 		if (!(val & APIC_SPIV_APIC_ENABLED)) {
 			int i;
 			u32 lvt_val;
-- 
1.6.2.1